I'm looking for a Windows RSS aggregator (freeware, shareware or money
up front ware) with a difference - I want it to retreive and locally
cache full articles, following (spidering) the link field specified in
the RSS feed.  I can then look through the full articles whilst
offline.

This is so I can have my laptop do a "grab" of feeds first thing in
the morning, and I can then read the full text of articles at my
liesure, whilst out of network range.
 
The perfect answer would be "what you need is xxx from yyy.com and it costs $z"

Thank you.

Here are two to try. Unfortunately, I wasn't able to check them out,
so I didn't post them as an answer:
http://rssowl.sourceforge.net/
http://www.newsgator.com/

Tried NewsGator, and it doesnt appear to do what is required. 
Interesting tool though, and if I used outlook for mail I'd probably
use Newsgator.

rssowl looked promising (it has a "save as" feature described in the
FAQ), but it doesnt like my Java setup so didnt actually work.